La Pavoni boiler question

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toolate

Postby toolate » Aug 01, 2018, 3:57 pm

I descaled my boiler with citric acid solution a while back. Most of the white scale is gone (still a few places with some) but I am concerned about the appearence of the boiler and wondered if the forums experts would have a gander at these two photos of my boiler to see what is up...the photos represent just a bit different lighting.
THe greeniish discoloration on the upper walls is?
The blackened area? Pitting? Scale?

THanks for any advice !

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ojt

Postby ojt » Aug 03, 2018, 3:10 am

Hi,

I'm no expert, but I have a brand new Pavoni and the boiler looks a bit like that. A non uniform brownish, with varying degree of darkness.

From what I've read this should be normal, but it is also said that descaling with citric might remove a natural protection the copper creates for itself (when oxidizing, I guess), and possible lead to further corrosion. Just google up copper corrosion and oxidation and you will find a lot of information.

All-in-all, yours to my eye looks good. But, let's see if someone more expert will chime in :)

P.S. I guess one could polish the boiler from the inside :) Not sure how useful that would be though.
Osku

toolate

Postby toolate » Aug 04, 2018, 2:42 am

Thanks! Anyone else with more boiler experience want to weigh in here please? :?:

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IamOiman

Postby IamOiman » Aug 04, 2018, 8:26 am

I have a 1991 Brass and Copper Professional. Here is my boiler from the top before and after I descaled with a citric acid solution. My result is a copper sheen on the side, though the brass flange appears to be similar to your sides. How long did you immerse your boiler in your descaling solution for? I have mine soak for 2-3 hours after heating up the machine then turning it off.

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ojt

Postby ojt » Aug 04, 2018, 4:31 pm

Here's mine, with water inside. Been in use for about two months. Looks like it did when I got it, except for the minimal scaling.

Sorry for bad lighting.. kinda hard to take photos of the boiler through the top :)

Anyway, doesn't look too different from the OP's machine

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Osku

toolate

Postby toolate » Aug 04, 2018, 4:46 pm

i should have pointed out i am taking photos from the bottom here after removing heating elelment.

But my greensih blue color is not seen in your two boilers...

ojt

Postby ojt » Aug 04, 2018, 5:33 pm

Yeah I noticed you took the photos from the bottom.

So if it is pitting, then what? Sanding and polishing all of it? I'm also asking for myself so I'll know what to do when the time comes.
Osku

toolate

Postby toolate » Aug 04, 2018, 5:38 pm

hopefully some knowledgeable soul roundhere can tell us

toolate

Postby toolate » Aug 04, 2018, 6:45 pm

Ok , WOW!
I had not done the simple step of reaching up inside the bottom and wiping the dark area with a cloth. :cry:

Just did so and was a bit alarmed to find it is black SLIME. (chemists on HB will appreciate the technical language here).

Now i am even ore puzzled; what is the black slime?

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IamOiman

Postby IamOiman » Aug 05, 2018, 1:14 am

toolate wrote:what is the black slime?


I am not completely sure, but I had it on my machine when I first purchased it. As a result, what I do when I descale my machine is fill it all the way to the top with the citric acid solution. The black stuff will come off after soaking with it for a few hours, then I rinse vigorously the whole boiler a few times.